Air filtration systems utilized in large ventilation systems in, for instance, buildings and power plants, often employ banks of elongated filtration bags or socks supported by wire filter cage assemblies. The filtration bags remove particulates from the air circulated through the bag. Due to the length of the wire filter cages, the filter cages are generally formed of two distinct sections which are fitted together, forming an elongate structure. A pair of clamps or hooks securely join the two sections on the outside surface of the wire filter cage. Air permeable filtration bags are positioned over the filter cages. The wire filter cages support the bags, and prevent the bags from collapsing as air is sucked through the bags. Particulates in the air accumulate on the outside of the bags as air is drawn through the bag and filter cage combination.
Drawing air through each bag from the outside to the interior allows for ease in cleaning accumulated particulates off of the bags. In particular, particulates can be removed by shaking the bag, or providing a ripple impulse to the bag, such that particulates simply fall off.
When the two sections of the wire filter cage are joined, the longitudinal wires of each section do not necessarily line up, but rather can be in a staggered configuration. As a result, the terminal ends of the longitudinal wires, which can be sharp and jagged, can be exposed at the junction of the two sections of the wire filter cage. The sharp or jagged ends of the wires can be filed or smoothed, but this is very labor intensive, with a marked increase in cost. The filter bags which are used in such a ventilation system are fragile and easily torn, and there is a danger that the filter bags will come in contact with the sharp or jagged edges of the wires at the junction of the two-part wire filter assembly, particularly during installation. The filter bags can accordingly often tear, rip, or run, rendering the filtration device less effective. Since a typical air filtration system may utilize in excess of twenty thousand filter cages and filter bags, ineffective filtration as a result of the damaged filter bags can cause a significant problem.